Mutations induced by 5-Bromo uracil are :-

Options

A. Transversional mutations
B. Transitional mutations
C. Frame shift mutations
D. Backward mutations

Answer

**Step-by-Step Solution:**

1. **Understanding 5-Bromo Uracil**:
- 5-Bromo uracil (5-BU) is a base analogue that can substitute for uracil in nucleic acids. It has a similar structure to uracil but contains a bromine atom.

2. **Mechanism of Action**:
- When 5-BU is incorporated into DNA, it can lead to mutations during DNA replication. It can pair with adenine instead of thymine, which can cause a transition mutation.

3. **Types of Mutations**:
- **Transition Mutations**: These are mutations where a purine is replaced by another purine (A ↔ G) or a pyrimidine is replaced by another pyrimidine (C ↔ T). Since 5-BU can mispair with adenine, it primarily induces transition mutations.
- **Transversion Mutations**: These involve the replacement of a purine with a pyrimidine or vice versa (A ↔ C or T, G ↔ C or T). 5-BU does not typically induce transversion mutations.
- **Frameshift Mutations**: These occur due to the insertion or deletion of nucleotides, which alters the reading frame of the genetic code. 5-BU does not directly cause frameshift mutations.
- **Backward Mutations**: These are mutations that revert to the original sequence. 5-BU does not induce backward mutations.

4. **Conclusion**:
- The primary type of mutation induced by 5-Bromo uracil is **transition mutations**.

**Final Answer**: Mutations induced by 5-Bromo uracil are transition mutations.

---